Windshield wiper mechanisms for windshields of motor vehicles are known, the windshield wiper being controlled not only via a conventional steering column lever but also additionally via an optical rain sensor. The optical rain sensor normally includes a light source, the electromagnetic radiation of which is reflected in different ways by the windshield as a function of the moisture coating on the windshield. The reflected component is detected using a photoelectric cell so that an output signal of the rain sensor corresponding to the moisture coating can be supplied. These output signals can be analyzed and used to control the windshield wipers in such a way that both the switching on as well as the wiper speed are varied as a function of a measured quantity of rain.
Known rain sensors are customarily mounted on the inside of the windshield, preferably behind an interior rear-view mirror. Cemented metal feet, for example, are used for mounting. Also known are mountings using an additional frame which is previously joined to the windshield and the rain sensor housing is pressed into it later.